CN2244110Y

CN2244110Y - Small backflow external circulation centrifugal pump seal device

Info

Publication number: CN2244110Y
Application number: CN 95214901
Authority: CN
Inventors: 凌玺
Original assignee: ZING XI
Current assignee: ZING XI
Priority date: 1995-06-09
Filing date: 1995-06-09
Publication date: 1997-01-01
Anticipated expiration: 2005-06-09

Abstract

The utility model relates to a centrifugal pump seal device with small inverse flow and external circulation. The utility model is characterized in that an inverse flow and external circulation device is arranged on the utility model by utilizing pressure difference between a seal box on the back face of a pump body and the negative pressure zone on the center of a pump head impeller, and liquid leaked in the seal box is sucked back into the pump; thus, the purpose that no leakage happens to the pump is realized. The utility model is composed of a flow collection box and a conduit pipe, and is connected in series between the seal box and the pump head. The utility model changes the existing seal mode, and has the advantages of raw material saving, cost reduction and reliable and durable seal performance. The utility model is especially suitable for conveying toxic and harmful liquid, and can be widely applied to the industry of petrochemical engineering, medicine and metallurgy.

Description

A kind of little backflow outer circulation centrifugal pump seal arrangement

The utility model belongs to the field of sealing technology of pump, relates to a kind of seal arrangement of centrifugal pump.

Centrifugal pump is when work, rely on the high speed rotating of impeller, liquid stream throws away by axially being drawn into radially, but also some liquid stream that is scattered collides on the pump case, accumulate in the zone at the impeller back side, when this part liquid exceeds external atmosphere pressure owing to constantly increasing of pressure, will between the slit of pump shaft and pump case, leak out, if what carry is poisonous, harmful liquid, will cause serious corrosion and pollution.Generally adopt packing seal and mechanical seal in the prior art, solve the leakage problem of pump.Usually at the impeller dorsal area, the place, slit that is pump shaft and pump case is provided with a sealed letter, tight with filler to pump shaft and pump housing sealed letter wall pressure, stop the leakage of liquid, but adopt this type of sealing often because the decentraction of pump shaft rotation, material aging etc., sealability is destroyed, thereby needed often to change filler.Another mechanical seal, though good seal performance, its cost height, working life is short, needs termination of pumping during replacing, difficulty is installed, but also can causes the pollution to environment.

The purpose of this utility model is to change traditional sealing means, without leak stopping, but adopts a kind of way of water conservancy diversion, utilizes the pressure reduction between sealed letter and the pump head, the liquid that leaks in sealed letter is sucked back in the pump, thereby the nothing that realizes pump is leaked.

The technical solution of the utility model realizes as follows: utilize the pressure reduction between pump housing back side shaft sealing letter and the pump head impeller central negative nip, a backflow external circulating device is set therein, it is made up of flow-collecting box and conduit, one end and the shaft sealing letter of conduit join, the negative pressuren zone of the other end and pump head is connected, flow-collecting box of middle serial connection is installed a check valve on the conduit between flow-collecting box and the pump head negative pressuren zone, a spherical body is set in the flow-collecting box.

Advantage of the present utility model is to have changed existing pump seal mode, utilize the pressure reduction between sealed letter and the pump head, as long as set up an external circulating device, just the liquid that leaks in sealed letter continuously can be siphoned away, need not change existing pump, just can realize not having and leak, stuffing box packing and mechanical sealing element in packing seal and the mechanical seal have been removed from, raw material have been saved, reduced cost, and sealability is reliable and lasting, is particularly useful for carrying poisonous, harmful liquid, can be widely used in industries such as oil, chemical industry, metallurgy, medicine.

Accompanying drawing 1 is a kind of general illustration of little backflow outer circulation centrifugal pump seal arrangement.

Be specific embodiment of the utility model below:

Flow-collecting box 6 is made by corrosion resistant metal titanium and plastics respectively with conduit 5.Have and the onesize opening of conduit 5 diameters on the intake pipe 1 before the bottom of sealed letter 3 and the pump head, one end of conduit 5 and sealed letter 3 are connected, the other end communicates with intake pipe 1, and the negative pressuren zone that inserts pump head forms a backflow, flow-collecting box 6 of middle part serial connection of conduit 5, a check valve 8 is set on the conduit 5 between flow-collecting box 6 and the pump head negative pressuren zone, prevent because of termination of pumping, pump head increased pressure and the refluence that causes, conduit 5 and sealed letter 3, the connection at places such as intake pipe 1 and flow-collecting box 6 is and is tightly connected, a bulb 8 is placed at bottom outlet place in the flow-collecting box 6, and available rubber is made, and intercepts gas with it.The scattered liquid stream of sub-fraction collides on the pump housing 2 when centrifugal pump is worked, when leaking and accumulating in the sealed letter 3 at the pump housing back side between slit by pump shaft 4 and pump case, promptly suck back in the pump via conduit 5, flow-collecting box 6, when in the case liquid being arranged, bulb floats, liquid passes through, and during no liquid, bulb falls seals outlet.

Claims

1, a kind of little backflow outer circulation centrifugal pump seal arrangement, comprise shaft sealing letter (3), it is characterized in that: between the pump housing (2) back side shaft sealing letter (3) and pump head impeller negative pressuren zone, a backflow external circulating device is set, it is made up of flow-collecting box (6) and conduit (5), one end of conduit (5) and shaft sealing letter (3) join, the negative pressuren zone of the other end and pump head is connected, a middle serial connection flow-collecting box (6), the conduit (5) that is connected between flow-collecting box (6) and the pump head negative pressuren zone is gone up a check valve (8) is installed, and a spherical body (7) is set in the flow-collecting box (6).